Page:American Seashells (1954).djvu/365

Rh mantle reflexed and closed over the shell, in lacking central teeth in the radula, and in having a much more degenerate shell. Genus Philine Ascanius 1772 Philine quadrata S. Wood Quadrate Paper-bubble Figure 596 Arctic Seas to North Carolina. /4 inch in length, moderately fragile, semi-transparent, white, squarish- oval and more constricted toward the top. Aperture large, flaring, and rounded below. Early whorls very small. Sculpture of numerous spiral rows of microscopic oval punctations. Suture deep. The narrow top of the aperture is slightly higher than the apex. Commonly dredged off the New England states from 20 to 400 fathoms. Philifie lima Brown File Paper-bubble Figure $^i Arctic Seas to Cape Cod, Massachusetts. H inch in length, much more oblong than quadrata, with the top of the aperture well below the apex, and sinuate from a top view. Columella fairly strong. Sculpture of spiral rows of scalloped lines forming chains, between which are a single scalloped line. Moderately common in fairly shallow but cold water. Ahas P. lineolata Couthouy. Philifie sagra Orbigny Crenulated Paper-bubble North Carolina to southeast Florida and the West Indies. % to /4 inch in length, oblong, fragile, white, with a large aperture, with numerous spiral lines of small oblong rings placed end to end, and char- acterized by the finely crenulated lip. Top of the aperture the same height as the apex. Not uncommon from 15 fathoms down. Family GASTROPTERIDAE Genus Gastropteron Kosse 181 3 Shell entirely internal and consisting of a minute, nautiloid, calcareous spire. Body sack-shaped, with two large, wing-like, fleshy flaps, one on each side of the body. These peculiar, small sea-slugs swim through the water in a bat-like manner. Gastropteron rubrum Rafinesque Bat-wing Sea-slug Figure 6oe West coast of Florida to the West Indies. Mediterranean.